where
\(\rho _i = \min \big (\bar{\rho }, \frac{\pi (a_i|s_i; \phi )}{\mu (a_i|s_i)} \big )\) 
and
\(c_j = \min \big (\bar{c}, \frac{\pi (a_j|s_j; \phi )}{\mu (a_j|s_j)} \big )\)  are truncated importance sampling [1]} weights. So the value function parameter is updated in the direction of:
\( \Delta \theta = (v_t - V(s_t; \theta )) \nabla _{\theta } V(s_t; \theta ), \) 
